With more than 200 million monthly active users, Twitter is among the Web's most popular social networking services, along with Facebook Inc, and is expected by analysts to float shares to the public within two years.
SAN FRANCISCO, March 26- Facebook Inc is expanding the advertising system that lets marketers tailor messages to users of the No. 1 social network based on their browsing history, in the company's latest step to refine its ad business.
MENLO PARK, Calif., March 7- Facebook Inc introduced a visually richer, mobile device-oriented "newsfeed" on Thursday, in the most significant changes to date for the social network's most recognizable feature.